Cell-to-cell communication in response of E. coli cells at different phases of growth to low-intensity microwaves.

Shcheglov VS, Alipov ED, Belyaev IY

Biochim Biophys Acta 1572(1):101-106, 2002

Effects of millimeter waves (MMW) at the frequency of 51.755 GHz were
studied in logarithmic and stationary E. coli cells at various cell
densities. The changes in the genome conformational state (GCS) were
analyzed by the method of anomalous viscosity time dependence (AVTD). Before lysis, the cells were adjusted to the cell density of 4x107 cells/ml and all AVTD measurements were run at this cell density.

Stationary cells
responded to MMW by increase in AVTD, while the same MMW exposure decreased
AVTD in logarithmic cells. MMW effects depended on cell density during
exposure and were stronger for stationary cells.

The observed dependence on
cell density suggested a cell-to-cell communication between cells during
exposure to microwaves. Decrease in power density (PD) resulted in more
striking differences between responses at different cell densities. The data
provided evidence that intercellular communication in response to MMW
depended on cell status and PD of microwaves.

The MMW effects were studied
in more detail at low intensity of 10- 1 7 W/cm2 in the range of cell
densities 4x107 to 8x108 cells/ml. The obtained sigmoid-like dependence
of MMW effect on cell density saturated at approximately 5x108 cells/ml.

The dependence of MMW effect on cell density was very similar in this study
and in previous studies with weak extremely low frequency (ELF)
electromagnetic fields (EMF). The data suggested that cell-to-cell
communication might be involved in response of cells to weak EMF of various
frequency ranges.